fix(runtime): stop the Windows daemon from opening a visible console

[Silversun31]

Fixes #172

Windows ignores CREATE_NO_WINDOW when it is combined with DETACHED_PROCESS. The venv
python.exe is a launcher, so the real interpreter it starts got a new visible console, and
closing that window killed the server.

spawn_daemon now uses CREATE_NEW_PROCESS_GROUP | CREATE_NO_WINDOW, the same flags the
worker processes already use (apps/admin_console/services/worker_process_io.py). The daemon
still outlives the terminal that started it.

test_spawn_daemon asserts the flags on Windows; it fails on the previous code.

Tested on Windows 11 with a uv venv: uv run artemis restart --no-open no longer shows a window
and the API answers. ruff format --check, ruff check, scripts/quality_ratchet.py,
pyright --project pyright-core.json and pytest (2528 passed) are clean.

🤖 Generated with Claude Code

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